Mangum was 16 of 30 for 284 yards and became the first BYU freshman to pass for over 3,000 yards in a season. Mitch Mathews had 158 yards receiving and two scores, including a 72-yarder for his longest career reception. He went over 2,000 career yards and tied a school season record with 11 TD catches.
Mangum's 35-yard TD pass to Mathews gave BYU a 31-21 lead in the third quarter and Francis Bernard added a 10-yard scoring run after Bronson Kaufusi's second blocked kick. This season, Kaufusi has four blocked kicks and BYU a national-leading eight.
Chuckie Keeton threw his 61st career TD pass for the Aggies (6-6) and also scored on a 52-yard option keeper. Keeton was 20 of 45 for 243 yards. Hunter Sharp had 100 yards receiving.
BYU (9-3) ended the Aggies' 14-game home win streak.